Electronic and magnetic ordering induced by Mo- and Ru doping of the Mn site in CaMnO3 perovskite: EMR probing - art. no. 10H704

摘要

X-band electron magnetic-resonance (EMR) measurements of polycrystalline CaMn1-yMoyO3 (0 <= y <= 0.14) samples were performed at 120 K <= T <= 540 K. The data obtained are compared with those of another electron-doped manganite system, CaMn1-xRuxO3 (0 <= x <= 0.40). The observed anomalies of the EMR parameters correlate pretty well with the temperatures of antifferro-, ferromagneticlike, and orbital/charge-ordering transitions in these systems. However, a strong difference is observed between the resonant properties of Mo- and Ru doped series at both paramagnetic (PM) and magnetically ordered states. To describe such a difference, the energy-band diagrams, which comprise the deep impurity t(2g)-like states +e(g)-like conductive band for CaMn1-xRuxO3 and shallow impurity states+conductive band, both having e(g)-like symmetry, for CaMn1-yMoyO3, are proposed. Specific electrons' contribution to the EMR linewidth at PM temperatures is introduced for the considered systems. (c) 2005 American Institute of Physics.